1. A method for controlling a nonvolatile semiconductor memory including a block which has a plurality of pages, the method comprising:
sending a request for a writeerase operation by a page unit to the nonvolatile semiconductor memory; and
managing, for each page, information associated with respective numbers of data writeerase times of the pages.
2. The method according to claim 1, further comprising:
determining whether perform a refresh to return states of memory cells of all the pages in the block based on the information.
3. The method according to claim 2, wherein the refresh is executed, when a total value of the number of data writeerase times reaches a predetermined value with respect to all the pages.
4. The method according to claim 3, wherein the information is initialized by the refresh.
5. The method according to claim 2, wherein the refresh is executed, when a maximum value of the number of data writeerase times reaches a predetermined value with respect to all the pages.
6. The method according to claim 5, wherein the information is initialized by the refresh.
7. The method according to claim 2, wherein the refresh is executed, when a value obtained by subtracting a minimum value from a maximum value of the number of data writeerase times reaches a predetermined value with respect to all the pages.
8. The method according to claim 7, wherein the information is initialized by the refresh.
9. The method according to claim 1, wherein the information is managed in the nonvolatile semiconductor memory.
10. The method according to claim 1, wherein the information is managed out of the nonvolatile semiconductor memory.
11. A method for controlling a nonvolatile semiconductor memory including a block which has a plurality of areas, the method comprising:
sending a request for a writeerase operation by an area unit to the nonvolatile semiconductor memory; and
managing, for each area, information associated with respective numbers of data writeerase times of the areas.
12. The method according to claim 11, further comprising:
determining whether perform a refresh to return states of memory cells of all the areas in the block based on the information.
13. The method according to claim 12, wherein the refresh is executed, when a total value of the number of data writeerase times reaches a predetermined value with respect to all the areas.
14. The method according to claim 13, wherein the information is initialized by the refresh.
15. The method according to claim 12, wherein the refresh is executed, when a maximum value of the number of data writeerase times reaches a predetermined value with respect to all the areas.
16. The method according to claim 15, wherein the information is initialized by the refresh.
17. The method according to claim 12, wherein the refresh is executed, when a value obtained by subtracting a minimum value from a maximum value of the number of data writeerase times reaches a predetermined value with respect to all the areas.
18. The method according to claim 17, wherein the information is initialized by the refresh.
19. The method according to claim 11, wherein the information is managed in the nonvolatile semiconductor memory.
20. The method according to claim 11, wherein the information is managed out of the nonvolatile semiconductor memory.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for the preparation of iso-polyprenols of the formula
wherein n is an integer of 6-10 and the dotted line means that a line is present or not, and wherein
the process comprises reacting a carbonyl compound of formula
\u2003with ethine in the presence of ammonia and an alkaline metal hydroxide in a non-polar, aprotic organic solvent or in the absence of organic solvents and optionally thereafter partially hydrogenating the resulting ethinol of formula
\u2003in the presence of a catalyst suitable for the selective hydrogenation of the triple bond to a double bond, wherein
the molar ratio of the alkali metal hydroxide to the carbonyl compound is in the range of 0.3:1 to about 5.0:1.
2. The process of claim 1, wherein the alkali metal hydroxide is potassium hydroxide.
3. The process of claim 1, wherein an aqueous solution of the alkaline metal hydroxide is used.
4. The process of claim 1, wherein the carbonyl compound is ethinylated in the presence of liquefied ammonia.
5. The process of claim 1, wherein the hydrogenation catalyst is a Lindlar catalyst.
6. The process of claim 1, wherein n is 8.